I find the easiest way to know if LIB and DLL function correctly, and avoiding confusion on correct setup is it just drop them all in the root directory of your project. VS should see them upon load of that project.

Once you've run the installer, you'll have a set of OpenMPI debug and release dlls, libraries to link to and the necessary include files. If you're installing the 64-bit version, it will end up here by default:

I just gave up and stuck with Unix/Linux. Eclipse IDE offers a very nice plugin for developing and debugging MPI code named Parallel Tools Platform. Something not available in Visual Studio, except for similar one made by Intel, but I believe you have to use their compiler.

You could always run Eclipse remotely from any Windows OS using a Secure Shell client and Xming (A Windows based X Server). That is what I do, and no more wasting time trying to get OMPI trying to run on Windows.

This may, or may not be helpful, but I have tried the Windows offerings. I have never gotten anything to function was expected. Compiling, or the available binaries. I think they just don't work at all.

My suggestion which I feel would be easier, and less headache way would be to install something like CygWin, which would give you a Unix/Linux like environment running under Windows.

You would only need to compile it in CygWin just like the Linux/Unix docs say to do.

I'm not sure how you can uninstall the other one, may be 'make uninstall' from the source? Or you may also ask in their mailing list.

Another solution might use the full path for the executables, like "c:\Program Files\OpenMPI_v1.6-win32\bin\mpicc hello.c" or under Cygwin: "/cygdrive/c/Program\ Files/OpenMPI_v1.6-win32/bin/mpicc.exe hello.c".

The output looks strange. If you use the installer under Cygwin, mpicc shouldn't try to link with liblammpio.* or any library in /usr/local/lib. So I guess the mpicc is messed up with some previously installed MPI implementations. Could you please verify that 'which mpicc' is the one you installed?

Anyway, here I sent some screen shots that how it should look like under Cygwin.

I ran OpenMPI_v1.6-1_win64.exe. Now I get this message: C9995799@SOUMIWHP5003567 ~/openmpi-1.6 $ mpicc hello.c -o hello WARNING: mpicc expected to find liblammpio.* in /usr/local/lib WARNING: MPI-2 IO support will be disabled gcc: hello.c: No such file or directory mpicc: No such file or directory--Vimal